1. Field of the Invention
The present invention relates to a liquid chromatograph such as a high-speed liquid chromatograph, and more particularly, concerns a liquid chromatograph, which has functions for trapping separated component(s) in a trap column for condensing the component(s).
2. Description of the Prior Art
In a conventional two-dimensional high-speed liquid chromatography, an eluent is divided into fractions containing one or more components to be analyzed on the downstream side of a primary analysis column so that the components are adsorbed in a trap column and the like for condensation, and then the components adsorbed in the trap column are desorbed for re-analysis in a secondary analysis.
Upon adsorbing the components into the trap column, in order to increase the adsorbing efficiency of the components to the trap column, a mobile phase, which weakens the solvent strength of the eluent, is sent simultaneously as a diluent. The mixing ratio of the eluent and the diluent, that is, the dilution ratio, is determined by using a resistance tube.
Upon sending a solution for condensation into the trap column, the ratio of a solution used for transporting the eluent fractioned in the primary analysis into the trap column and the diluent effects the adsorbing efficiency greatly; and in the conventional device, since the selection of the dilution rate is made by using a resistance tube, the dilution rate is limited to several values such as 1/3, 1/6 and 1/10, and thereby fails to properly provide various dilution rates.